A method and system are described for the purpose of timing various functions of the vehicle and determining the overall response of a vehicle in non-professional or xe2x80x9csportsmanxe2x80x9d bracket index drag racing competition. More specifically, the method and system utilize sensors and a microprocessor to calculate and store to memory elapsed times between vehicle functions and with a delay, display these times to the user.
In bracket drag racing, where there are numerous drivers who compete in heats comprising two drivers, there are two criteria that a driver must meet to win the race. First, the driver must cross the finish line sooner that the other driver in their heat. Second, the time of the winning driver in each heat is compared with a target time. The driver who wins his heat and comes closest to the target time without going under the target time wins the overall race. For example, in a race with a target time of 8.90 seconds, a driver who reaches the finish line with a time of 8.89 seconds will lose the race to the driver whose time was 8.906 seconds. Therefore, in this type of racing, accurate timing is as critical as winning the race. There is a need for drivers to measure every aspect relevant to the vehicle acceleration functions.
It is common at the beginning of the race for the driver to engage a transbrake, which engages both the reverse and first forward gears of the transmission. By forcing the torque of the engine into both directional gears, the one negates the function of the other and the vehicle is kept still. The transbrake is kept engaged by the driver holding down a release button on the transbrake control panel. To begin the race, a number of lights at the starting line of the race track are illuminated in sequence (amber-green) to signal to the driver the start of the race. When the green signal is indicated, the driver releases the transbrake button, which in turn releases the transbrake. The release of the transbrake causes the engine torque to act on a driveshaft, causing it to turn. The vehicle then begins to accelerate.
As mentioned, it is important that the driver match the target of xe2x80x9cindexxe2x80x9d without going under it. To this end, a device known as a xe2x80x9cthrottle stopxe2x80x9d is commonly used in drag racing to partially close the throttle for a pre-selected time period during the race. It is necessary for the racing vehicle to have sufficient power and speed capacity to complete the race in a time shorter than the index time, so that the vehicle will be competitive under all racing conditions. Consequently, although the vehicle is normally run at wide-open throttle to reach maximum acceleration, the throttle cannot be kept wide open for the entire race without exceeding the xe2x80x9cindex timexe2x80x9d for the race. Thus, the throttle stop is used to partially close the throttle for a brief period that is selected to cause the vehicle to complete the race in a time that is as close as possible to the index time. When the throttle stop is released at the end of the pre-selected time period, the throttle returns to its wide-open position until the driver releases the accelerator pedal at the end of the race, commonly referred to as xe2x80x9cthrottle liftxe2x80x9d. Both the beginning and ending times for the throttle-stop period are selected before the race based on anticipated race conditions.
All of this activity normally occurs in races of approximately nine or ten seconds. Due to the compacted time frame of the races, there is a need for accurate timing, and it is important for the driver to know how long various activities take, after the vehicle controls have been prearranged to accomplish the task of winning the race. By being able to accurately time various functions of the vehicle, the driver can better adjust the overall performance of the vehicle.
Typically, other devices are utilized which measure one aspect of the vehicle reaction time. For example, some devices only measure the time between the driver""s action that starts the forward motion of the vehicle and attainment of a predetermined forward accelerating movement of the vehicle. Although this information is helpful to the driver, more specific and additional times are needed.
Another existing device collects information relevant to various electrical and mechanical functions of the vehicle. This information is then displayed in a graph-style format either in print or on a personal computer screen. To differentiate the relationships of the various activities measured, the driver or interpreter must chart those relationships in correlation to one another on the graph. This process is time consuming and subject to human computational errors.
It is therefore an object of the present invention to provide a novel and improved timing device which overcomes the above-noted problems in the prior art.
It is a further object of the present invention to provide a timing device to measure elapsed times between a variety of related events in a drag racing vehicle.
It is a further object of the present invention to provide a timing device which displays the elapsed times in a user-friendly format that does not require lengthy computation by the user.
In the preferred embodiment and in accordance with the above-mentioned objects, a timing device is provided for measuring elapsed times between related events in a drag racing vehicle having an engine, a transbrake, means for engaging and disengaging the transbrake, a driveshaft, a throttle stop mechanism, means for activating and deactivating the throttle stop mechanism, a delay box, and an accelerator pedal. The timing device is comprised of means for sensing electrical signals in response to (1) release of a transbrake button or other means for engaging and disengaging the transbrake and (2) actual release of the transbrake. The timing device further includes a means for measuring the elapsed time between the electrical signals so as to measure the elapsed time between release of the transbrake button and actual release of the transbrake. The elapsed time is displayed in an alphanumeric format, so that it is easy for the user to read and understand.
In the preferred embodiment of the present invention, electrical signals are also sensed when the driveshaft begins to turn, when acceleration of the vehicle reaches a selectable, predetermined value of either 0.5 or 1 g force, upon engagement of the throttle stop mechanism, upon disengagement of the throttle stop mechanism, and when the accelerator pedal of the vehicle is released. These elapsed times are measured between the release of the transbrake and each of the above-listed events. All of this information is available for display twenty seconds after the release of the transbrake, on a display screen in an alphanumeric format.